Impeller for mechanical dishwashers



Dec. 30, 1930. F. A WALKER 20 IMPELLER FOR MECHANICAL DISHWASHERS Filed Nov. 25, 1926 04 ATTO NEYS.

. 192e,-and ref im ej io ich a limited quantit I IIium-lresistanceandpower,

* "Q bi snd u e re ung to as Patented Dec, 30, 1930 oagom'rroitror synacusumuw You, .aooaroaarxouor YORK a mamas-rehash a mechanical dish jv washer ofthe class setjforth in my pending a'p'plic'atioiiv Serial .No. {122,277, filed July 14,

, In machines 02E;this type the dishes and other utensils to be washed are supported in suitable f'open work trays cylindrical vat having "a conical bottom in v of washing fluid is'g'iplaced' to be im" elle or "circulated up;

a wardl fand-circum erentiall 'by'fthej rotary impeler jwhich'isp'laced'wit inandinclo'se I proximity. to tliefconical bottom in a' plane i5 belowl the dish-supporting tra s and' driven L by afvertical shaft'extending in'the apex ofsaid bottom.

"Under. these conditions it'- is highly pprta mhaeth washing fluid be. impelled i "20 upwar y with r ionsiderable 'force and in such" manner; as toefiect' a glancing contact witlivall of the disliesi 01 otherp'utensils throughqut'the areaoithe superposed trays as inventing isto accomplis fathis result ins-the most eiiicientand-expeditiousmanner with a minimum consumption of power by reducing the centrifugal: motion of the flui against a continuousbafile connecting the :outer edges oi. the-im eller blades in sp'aced relation to *the-hubo theimpellerrluwotherlyvorclsl one ofthe ohjects is tor-Jon struct the impeller blades in such manner that 35 t a, a

they will pick ppiandj defiect the fluid upj Wardlyl Eand lc'ir' uiii ferentially "with Another object 18 m mutiny-inclines lower-sends of the blades 7 more nearly toward "a horizontal plane and anddeflect it against the baffle band during the: initial pick-u of the water bythe blades and to utilize the afile band as the means for force. of upward'deflection of the fluid and I baflle resistance of the band for efiecting the continued upward movementof the fluid with "aminimum consumption ofpower;

' it mtr easm taps,pz a $150,230.

particularly to the I c construction of the impe peller with the baflle band thereon,

or baskets 'within'a th eu l efl upon the upper end oft 'e post has its upper; end provided 1 2 f mu a g stagnant:

, f. mm wanna-es;muse,mwomimmnos rofwatima amas parts of-tlie device will be brought out in following description.

-In the'drawingsawv ,2 Figure 1 is a top planof the detached imshowing the baflle ring partly broken away and one of the blades partlyin section. Figure 3 vista vertical "sectional view taken on-line 3+3, Figured. l a I Figure-4 isase'ctional .view on a reduced scale of the im eller and adjacent portionsof the vatrin WhlCh it is located to ther with portion of the drivingfshaft, or the-impelle'r.

"-As' shotn ih the top or vat is ,pro-

having anopening in its apex in which is secured the lower end of a*postr-2-- to form a water-tight gland therewith, the upper end of the post extending some distance'above the apex of the. bottom -1-'- for receiving-and "supportmg a rotary vertical shaftp-3-having its upper end 'extending beyond thetop of the post and for-receiving .the' impeller The'im eller -4- comprises an upri ht hollow tu ular hub -5- having a lurafity of, in this instance two, diametrica y oppositeand laterally projecting blades'-'6-, the

outer edges of which are'connected by acoujtinuous" 'circumferentially e'xtending' annular band or bafile ring -7- which together with the blades 6 and hub -5- are referablycas't of aluminum or other suita le material to form a sin 1e unit but obviously may otherwise be assem led if desired post -2 extending into the vat -1- while I the interior diameter "thereof is slightly in such manner'as'to -graduallylift-the fluid greater thanthe diameter of said post, saidhubwith the impeller blades ?6 and baflie "Ifhelengthof the hub -'-a-" slightly v greater than the' length of the portion of the lowjthebafle'band as to cause the latter to tighten when in op V v removal of the impeller e fromthe shaftwhen eration and also permitting easy and quick at rest.

It is now clear that the impeller issuported entirely-upon its upper end upon and" I ls'drivenby-the shaft-with its remaining portions ors'kirtencircling the post +,-2+4.with

-e.5?fand post to ayoid friction one with the with; 1

, Thesimpeller maintained eta re-determined;level"at 'or near th'e'levelro "the-top, of; the 'im elle'r "blades, the lower. ends" ofgsaidwblades' eingv with justsnflicient clearancetoyavoid U y wand particnlarly-thev ront facesthereofare *snbstantiallytangentialto the corresponding sides of thje hub while the outerfportionsiare actively disposed in proximity to the bottdm Contact erewith;

i p The diameter;-ofithes impeller is 4 ablyless than that ofthe'yeylindrical; side;

walls of the vat-and-isrregnlated isomewhat 1 by x the" inclination bf the ibottom and by the' normal" depth of the washing -5fluid thereinsoithat the lower}. edge of the baflle ring 7 will lie inclose proximity-tosthe I adjacent portion' of the bottom with just suflicient clearance to. 1 avoid contact therewith while-"its upperiedge williberat 'orfnear the level of therwa shing fluidtpreferably: disposed in the s'am'e'fhoriz'ontalp vatythebafile ring being preferably cylindrian. and concentric with the axis of the "impeller; f 1

T to :the amountlof projection and forward into" v :frontfacethereof is'curved clination of-the-lower portions of the; blades -f orwa'rdly from its. upperedge to ;-its lower edge with gradually diminishing-radiiin-the blade as shown moreclearly in Figure-2 the 7object of which isu-to permit the lower--free {edge of thedblade' to 'enter the fluid with a. minimumresistance by thee inertia o-f said V fluidand theritograduallylift or deflectthe. {1,1 my I if when the-impeller is installedin thev Vat fluid upwardly {and rearwardly against; the

is-rotatably supported within theapex'ofthe bottom of the vatand; therefore; within the greatest depth -.of.th .e

: washing fluid therein,whi chfluidais normally v I anerwhile the vertical depthof J the bladesl :is? considerably} greater- 4 than-that ofthetb'aflie ringz'duepartlyto the conical-formationofthe-bottom -i1'-- ofrthe wardlyand @9 9 theflim serveto distributetheiwashingsfliiidil war 1y and circumferentially withja consi enable force overa relatively lar e area and through the, superposed openwor 'f trays," not shown, carrying; the dishes and other utensils to; be washed; V. .3 a n gradual upward deflection of the water aided by the momentum of the latter ash; is picked It will be noted u on reference to Figure 2'that the angles of t e ortions of the blades between,.thelower an upper ends of the baiflej'ringf"7 are moreinearly vertical, than thelower ends of the blades which are more nearly horizontal and it is-found that for the spee'd' wi'th which this im eller' is .rotatedzthe ij a "best-results are obtained v yimakingithe porv tionof the blade between the up er and lower endstif the bafiie' ring at an ang e of approximate y; .0 d ees t th axis of the imp e 'jthis' angle 'graduallyincreasing toward a honizonalvat-at h l wer trout ed ef bafilefthus producing ajcuryedlimpact "face whichis found toebe the mostjeflicient in lift-f .ing" and distributin the ,w t ga a n dishes with a minimum w r 1 4 a It w'llalso be noted lponrefe ence'toFi'g ure -1 that the inner ortionsi oftlie blades radually curved inthe direction" of rotation tend some jdistancebelowthe'lower endiofthe, I

fhub andare gradually curved outward o ly-and-n "The upper edges of the blades' ,-6-+ -and pwa'rdly from said hub, thej. f ront thereof enterthefluid-with a inimumr slse v ance asthe impeller'is'rotatedjinthe direetion lf a dlt eil indicated by arrow a ly fl t h ifiui upw rdly nds ufi-v' wardly across the front facesthe'reof, theout;

ward. and u ward .curv'atilre ofthe lower; ends I 1 offthe bla esxserving to 'counteractlthejcen- 1 trifugal throw of. the. watervto' ascertain ext-f tent. a .7 1

"-.Th ;bafileiring 7 islarrangedtojcatch he wa e -d cte u w rd yyby h owe e I -.ends 'o'f the.- bladesanl Qinturn ag in deflect direction of rotation V topform-substantially one-halfofxa parabola.", the inclination of the a lower-portions of the'blade'sbeing gradually 5 but more ,-.abruptly increasedito; a horizontal -3a's it approaches thexlowerfreeedgegof the the water 1 ipwardliy soithat the 'combinedjc er blades and "bafli'e' rin attainif a J izo sired speed the washing fluid is first picked upby the substantially horizontal lower front edges of the blades with a minimum resistance and is thereby given a slight upward deflection which is gradually increased as it follows up the incline of the blades, the upward momentum imparted to the water being gradual but accelerated as it approaches the to of the blades thereby producing a consi erable upward and circumferential velocity of the water with a consumption of a minimum of power and at the same time directing-the washing fluid over a relatively broad superposed area.

It is found, however, that by connecting the outer ed es of the blades with a continuuous baflle ring such as -7 in su erposed relation to the lower ends of the bla es where the centrifugal throw is greatest retards this centrifugal motion of the water and deflects the same upwar'dly over a still wider area than that produced by the impact of the water with the front faces of the blades and by properly proportioning the diameter of the 'baflle ring and its vertical hei ht with reference to the lower ends of the aflie I am enabled to direct the washing fluid u wardly and circumferentially with considera le force throughout the horizontalarea of the superposed portion of the vat containing the trays with the dishes therein, it being understood that after the water has been impelled upwardly to the maximum it falls back by its own gravity to the conical bottom of the tub when the operation is repeated to establish a continuous upward and circumferential circulation of the washing fluid.

It is evident, however, that the construction and relation of the blades and baflle ring may be varied ta corres ond to difl'erent s eeds of rotation and to iflerent degrees of inclination of the bottom of the vat and alsoto variations in the diameter of the vat and distance of the-dish-supporting trays above the impellerwithout departing from the spirit of this invention.

What I claim is 1. An upright impeller for mechanical dishwashers comprising a hollow hub provided with outwardly projecting blades having their lower ends extended below the lower end of the hub and curved in the direction of rotation to a substantially v horizontal from top to bottom thereof and the lower end "of each blade being extended forwardly in a plane at substantially right angles to the axis of the hub.

3. An impeller as in claim 2 in which the outer surface of the hub is flared outwardly and downwardl from top to bottom for deflecting the fail ing dishwashing fluid outwardly against the blades.

4. An upright impeller for mechanical 

